Active oxygens are deeply involved in biophylaxis and signal systems between cells in the living body but, on the other hand, it has been revealed that active oxygens cause various oxidative damages on tissues and components of the living body and thus active oxygens damage human health and cause acceleration of aging speed.
As the active oxygens, there are radical species such as a superoxide anion (.O2-), a hydroxyl radical (.OH—), a hydroperoxyl radical (.OOH), an alkoxyl radical (LO.), and an alkylperoxyl radical (LOO.) which are formed by reduction of a part of oxygen at the time when mitochondria produces energy within cells in the living body through metabolism of oxygen, and non-radical species such as hydrogen peroxide (H2O2) formed from the superoxide anion, singlet oxygen (1O2), peroxy nitrite (ONOO—), lipid hydroperoxide (LOOH), and hypochlorous acid (HOCl).
It is known that these active oxygens may damage DNA's and body tissues to cause development of malignant tumors and may cause ischemic diseases such as cardiac infarction and angina, liver damage, cerebrovascular disorder, Alzheimer type dementia, diabetes, gout, nephritis, cataract, blotches on skin, wrinkles, and freckles.
Since the prevention of the damage caused by the toxicity of these active oxygens may lead to prophylaxis of these diseases, many antioxidant substances having active oxygen-removing ability have been proposed.
However, in an epidemiological survey on the relation between ingestion of antioxidant supplements (vitamins A, C, and E, β-carotene, selenium) and death disclosed in Journal of the American Medical Association published on Feb. 28, 2007, there is a report that mortality of persons who ingest the supplements other than vitamin C or selenium rather increases. Thus, it has been increasingly widely recognized that continuous ingestion of single antioxidant substance is bad since such ingestion breaks down the antioxidation balance in the living body (see Journal of American Medical Association, Vol. 297, No. 8).
The human body is separated into oil-soluble parts represented by cell membranes and water-soluble parts such as cytoplasm and blood, and there are reports that a preferable effect is obtained by combining a plurality of antioxidant substances (JP-A-2000-189102 and JP-A-2004-530407).
Particularly, an antioxidation network is present within the body and it is said that mainly thioctic acid has an action of recycling water-soluble and oil-soluble antioxidant substances and improving the life of their effectiveness (Antioxidant Miracle (written by Lester Packer, published on Jun. 20, 2002, Kodansha Ltd.)).
Moreover, there are antioxidant enzymes having action to counter active oxygens, such as superoxide dismutase and glutathion peroxidase. They use selenium, zinc, manganese, or copper, which is called an antioxidant mineral, as an active site and the antioxidant enzymes can be activated by ingesting individual minerals. Furthermore, by ingesting them together with the above water-soluble and oil-soluble antioxidant substances, it is possible to improve the antioxidation balance in the body.
The minerals are used as inorganic salts but recently, they are provided in the form of a mineral yeast wherein a mineral is incorporated into a yeast to aim at improvement in stability and increase in absorption efficiency (JP-A-2000-125811).